Believes that abnormality is when a behaviour isn't sociallyacceptable.
Dependent on the culture where the behaviour occurs- social norms aren't the same across different societies, so what is abnormal in one might not be abnormal in another.
Strengths of the definition:
Theoretical value- allows society to be predictable using social norms
Generalisable- the definition is flexible meaning it can be generalised to other situations
Limitations of the definition:
Low temporal validity- social norms change often, meaning a social norm might not apply to the future
Cultural differences- it isn't clear what is deemed abnormal or not in different cultures